There is no tutorial.

You have to dig into the code:
http://anonhibernate.labs.jboss.com/trunk/HibernateExt/tools/src/java/

and to guess the classes and properties from the freemarker names, e.g. c2h is for Cfg2HbmTool.java

To get some general ideas about hibernate tools, see:
http://www.hibernate.org/hib_docs/tools/reference/en/html_single

Same thing for me,

I'm trying to modify the list.xhtml.ftl file to add a comparaison if the field is the key. 

Even if there is no tutorial, can someone give us the object which contains the method of pojo like pojo.isComponent ?

Thank you
 

I'm not sure of what you want, but for comparaison if the field is the key, try something like:

<#foreach property in pojo.allPropertiesIterator>
    <#if ! property.equals(pojo.identifierProperty) />
        [...]
    </#if>
</#foreach>

Exactly, you have to dig in to the code in http://anonhibernate.labs.jboss.com/trunk/HibernateExt/tools/src/java/ it is initialized in the constructor of org.hibernate.tool.hbm2x.AbstractExporter

public AbstractExporter() {
     c2h = new Cfg2HbmTool();
     c2j = new Cfg2JavaTool();          
}

as you can see, it is as Pierre Raoul wrote, of type Cfg2HbmTool.

On the other hand pojo IIRC is of type org.hibernate.tool.hbm2x.pojo.EntityPOJOClass (also found under /HibernateExt/tools/src/java/)

If you have more questions on the inner workings of seam-gen, it could be a better idea to post the on JBoss tools forums

Regards,